METHOD OF LOCALIZED MODIFICATION OF THE STRESSES IN A SUBSTRATE OF THE SOI TYPE, IN PARTICULAR FD SOI TYPE, AND CORRESPONDING DEVICE

摘要

A substrate of the silicon on insulator type includes a semi-conducting film disposed on a buried insulating layer which is disposed on an unstressed silicon support substrate. The semi-conducting film includes a first film zone of tensile-stressed silicon and a second film zone of tensile-relaxed silicon. Openings through the buried insulating layer permit access to the unstressed silicon support substrate under the first and second film zones. An N channel transistor is formed from the first film zone and a P channel transistor is formed from the second film zone. The second film zone may comprise germanium enriched silicon forming a compressive-stressed region.

主权项

1. A method of localized stress modification in a substrate of the initially tensile-stressed silicon on insulator type, said substrate comprising an initially tensile-stressed semi-conducting silicon film disposed on a buried insulating layer which is disposed on an unstressed silicon support substrate, the method comprising:
forming at least one opening in the initially tensile-stressed semi-conducting silicon film and in the underlying buried insulating layer until the unstressed silicon support substrate is reached, performing a silicon epitaxy in the at least one opening from the unstressed silicon support substrate so as to fill in the at least one opening, performing a localized amorphization of a zone of the initially tensile-stressed semi-conducting silicon film including silicon epitaxy in the at least one opening, and recrystallizing the localized amorphized zone by a solid-phase epitaxy from the unstressed silicon support substrate situated in the at least one opening so as to obtain at least one localized film zone comprising tensile-relaxed silicon.